Hi Sally, Just found your post. I am the GGGrandson of Juana Briones. I have never been able to find an exact year of the birth for Marcos or his father Ygnacio, but found a Marriage Cert which lists Ygnacio's wife as Marsela Antonio Padron, dau of Jesus Nicolas Padron and Simona Morales.
I have Marcos marrying Maria Ygnacia Ysidora Tapia, but never have seen any record of a marriage to a Maria Guadalup. Marcos and Maria had twelve children, 5sons, 7daughters. Also, Ygnacio's parents were Francisco Briones and Manuela Ma. Loredo of Santa Maria del Rio, State of San Luis Potosi, Mexico.
Take care
Patrick Garcia
garce1947@yahoo.com